Ceramic molding press



Feb. ll, 1947. G. CHERRY HAL CERAMIC MOLDING PRESS Filed Aug. .lQ, 1943 3 Sheets-Sheet l Feb. 11. 1947. G. l.. CHERRY Em' 2,415,462

' l CERAMIC MOLDING PRESS Filed Aug. 10, 1945 3 Sheets-Sheet 2 A TTOR/VEY Feb. 1.1, 1947.

G. L. CHERRY ET AL CERAMIC MOLDING PRESS Filed Aug, 10, 1943 3 Sheets-Sheet 3 invention, a slug,

Patented; Feb. 11, 1947 Umso -smrlais .PATENT oFFic-e f George L. Cherry,

C. Veale, Wheaton, Electric Company,

Western Springs, and Charles Ill., assignors to Western Incorporated, New York,

N. Y., a corporation of New York Application August 10, v1943, Serial No. 498,078

2 Claims.

This invention relates to ceramic molding apparatus and more particularly to an apparatus for making slugs of ceramic materiaL'to be later extruded in the forming of articles.

It is an object of the present invention to provide a simple molding apparatus for quickly forming articles.

In accordance with one embodiment of the to be later extruded in the process of forming ceramic articles, is compressed between a pair of molding plungers positioned along a single axis and movable in a compressing cylinder and wherein one of the rams is driven differentially to quickly moveto position after a supply of material has been placed in the cylinder. The operation of the apparatus may/ be initiated by closing a guard member-surrounding one of the compressing plungers, thereby to set in operation a uid pressure system to move the upper of the two ramsinto the compressing. cylinder; Automatically operable means are provided to evacuate the compression chamber when the upper ram moves to position in the compressing cylinder.

A better understanding of the invention may be had by reference to the following detailed description when considered in conjunction withV the accompanying drawingswherein Fig. 1 is a front elevational View on a relatively small scale of an apparatus embodying the invention;

Fig 2 is a transverse vertical sectional view taken substantially along the line 2 2 of Fig. 1 in the direction of the arrows, parts being broken away to conserve space and both Figs. 1 and 2 showing the rams in their inoperative with the movable guard member open;

Fig. 3 is a horizontal sectional view taken substantially along the line 3 3 of Fig. 1 in the direction of the arrows and showing details of the guard mechanism and rial may be deposited in the apparatus;

Fig. 4 is an irregular fragmentary vertical 'sectional view taken substantially along the line 4 8 of Fig. 3 in the direction ing details of construction of molding cylinder and the upper ram;

Fig. 5 is a fragmentary detail sectional View taken substantially along the line 5 5 of Fig. 3 in the direction of the arrows showing some details of construction of a hopper provided for feeding ceramic material into the molding cyl.- inder; and l Fig. 6 is a schematic diagram of the fluid' pressure circuit of theapparatus showing the comof the arrows show-v position means whereby matethe -compressing or pressing rams in their operative positions and showing the various valves for controlling the rams in their operative positions.

l Referring to the drawings, wherein like reference characters designate the same parts throughout the several views, particular reference being rst had to Figs. 1 and 2, a base casting Ill is provided with a at bottom portion II, a ange portion I2, and a cylinder portion I3. This casting serves to. support the entire apparatus.' Standards I4 and I5, having reduced shanks I6 and Il, respectively, which are threaded to receive retainernuts I8 and I9, extend through the ange portion I2 and are attached thereto by'A means of'the retainer nuts.' The standards Ii and I5 are also reduced at their upper ends, as shown at 20, to receive a mold supporting blockor bolster 2l. The block 2I has a shouldered aperture 22 formed in it, in which a mold chamber 23 may be fixed by means of machine screws M M. 'I'he mold chamber is adapted to receive a cylindrical ram 23, which is mounted upon an upper end of a piston rod 26. The piston rod 264 is suitably attached to a piston 21, slidable in the cylinder portionk I3 of the base casting Iii,

ysuitable packing glands 28 and 29 being mounted to encircle the piston rod 26 and seal the lower end of the mold chamber 23 and a cylinder cap 30, respectively, the cylinder cap being suitably mounted to close the upper end of the cylinder portion I3. The cylinder portion I3 of the base casting I0 has aninternal shoulder 3l, against which the piston 2l will strike when the piston is moved to its lower position and the cylinderv portion I3 has an aperture 32 in which the end of a pipe 33 is threaded. Similarly, the cylinder cap 30 is provided with an entrance aperture or port 34, into which a pipe. 35 is threaded.

yFrom the foregoing, it is believed to be appar,-

ent that the piston 26 may be raised by feedingma uid .under pressure through the pipe 33 and permitting Huid in the upper portion of the cylinder I3 to escape through the pipe 35, and, in a similar manner, by supplying fluid under pres-r sure through the pipe 35, and permitting the escape of iluid through the pipe 33, the piston 26 may be lowered.

The reduced portions 23 of the standards I@ and I5 which 4extend above the mold supporting block 2i are surrounded by sleeves 45 and dii,y respectively, and on the upper ends of the sleeves there is positioned a cross head 67, which has a cylinder formed integrally with it. 'I'he cross head 41 is held in place on the sleeves 45 and 46 by means of two retainer members 49 and 53,

have notches 33 vand -tom end oi the hopper together by means of machine screws 3 v"nich are threaded onto the ends of the standards |4 and |5. The cylinder 43 is quite similar to the cylinder portion |3 of the base casting I in that it'has a closure member 5|. suitably attached to it, similar to the cylinder cap 30, and the inner surface of the cylinder 48 has an abutment member 52 formed on it for limiting the upward movement of a piston 53. Fluid under pressure may be supplied to the upper end of the cylinder 48 through a pipe 54 and entrance port 55 vand may be supplied to the lower end of the cylinder 43 through an entrance port 56 and pipe 51. the port 53 being formed in the closure member 5|. A packing gland serves to seal the cylinder 43 against leakage. where a piston rod 53, secured to the piston 53, enters the cylinder through the closure member 5|.

By reference to Fig. 4, it will be seen that the piston rod 58 has a head portion 85 formed on it and is provided, as shown in Fig. 3, with diametrically opposed guide portions 66 and 61, which 68 formed in them for engaging guide rails and 1l, which are suitably attached to the sleeves i5 and 48, respectively, and serve to guide` the head portion 65 when the piston 58 is reciprocated. Set into the underside of the head portion 35 is an annular resilient gasket 12, adapted to engage the upper surface of the mold chamber 23. The gasket 12 is set into an annular shoulder 13 formed on thehead portion concentric with a cylinder closing plunger 14, also with the head portion 65. The plunger 14 :and the shoulder 13 define an annular groove 15 extending around munication with a passage 18. The passage 15 is, in turn, in communication with an entrance port 11,\which may be closed by a valve comprised of a head 13 and a. stem 19. The stem 19 is slidthe plunger and in com` able in an aperture 80 and the head 18 is normally urged to engage a valve seat 8| by a compression spring 82 bearing against a plug 83, in turn threaded into an aperture 34 in the head portion 65. Threaded int'o the entrance port 11 is a. pipe 85 connected to any suitable vacuum pump (not shown), which will tend to draw any air 'which might be entrapped in the mold chamber 23 out of the mold chamber so that when a mas-s of ceramic materials 33 is positioned in the mold chamber and pressed between the ram 25 and plunger 14, no air will be trapped in the'slug of material formed between the ram and plunger in the mold chamber 23. The plunger 14 is made slightly smaller in diameter than the inside diameter 'oi' the chamber 23 to provide a. small clearance between the plunger and cylinder to let air pass the plunger but not the granules oi ceramic material.

Pivotally mounted on the mold supporting block in the direction indicated by 2| at 90 is a bracket 0| (Figs. 1 and 3), which has formed integrally with it support 92. The support 32 is attached t a base ring 93v which 'forms the base of a hopper designated generally by the numeral 94 (Figs. 3 and 5). In addition to the base ring 93, the hopper includes a body portion 85,' the lower end of which is tapered to nest in the base ring 93. The bot- 31 and 38 attached 39 and clamping an annular resilient member |00 be- 96 comprised ci two plates ytween them. The annular resilient member |00 bears against the inner surface of the base ring 93 and normally tends to hold the gate 03 in the position shown in Fig. 5. Set into cooperating notches |0| and |02 formed in the plates 31 and an arcuately shaped 94 is provided with a gate control a pilot valve 98 is a square portion |03 of a shaft |04, which is rotatable in opposite sides of the ring 93 and which has a handle |05 iixed to it whereby it may be manipulated. The hopper 54 may be filled with ceramic material. to be molded in the apparatus with the gate 96 inthe position shown in Fig. 5 and may then be swung into position above the mold cham-ber 03 and may then be manipulated to drop the ceramic material 83 to the position as shown in Fig. 4 while the rams 25 and 14 are in their retracted position opposite to that shown in Fig. 4.

The rear of the apparatus is enclosed by a guard screen H0, which extends around the rear of the head portion 35 on the piston rod 58 and will prevent anything from being accidentally inserted beneath the ram 16. In addition to the screen ||0 guarding the rear of the apparatus, a slidable screen is provided for guarding the iront of the apparatus. The screen is provided with four guide rollers H2, H3, ||4 and ||5 (Figs. vl and 3), which ride upon guide rails H6 and ||1. The guide rails ||6 and ||1 are mounted at the forward ends of brackets ||3 and H9 iixed to the faces of the sleeves 46 and 65, respectively. The guide rail H6, as shown most clearly in Fig.v 1, has a pivoted iatch 12u pivoted thereon for eugaging in a notch |2|- when the screen is moved to its lower position, opposite to that shown in Figs. 1 and 2, thus to latch the screen in its downward position. The screen is normally urged to the position shown in Figs. 1 and A2 by a pair of weights |22 and |23, which are interconnected withthe screen by a pair of pulleyV cords |20 and |25, which pass over grooved pulleys |2t and |22 mounted on brackets |28 and |23, respectively, which are, in turn, mounted upon the sleeves t8 and t5, respectively. The screen may be lowered by means of a handle |30 attached thereto and may be latched in its down or closed position by the latch |20.

Fixed to the screen 'i i is an actuating arm |40, which extends into the path of arms iti and |42 of a V-shaped lever |43, which is adapted to M4 to move the valve to the position shown'in Fig. 6 when the screen is moved to its closed position. When the screen is moved to its closed position, the weights |22 and |23 will travel upwardly in guides |34 and |35, respectively, which are attached to the sleeves B6 and 55, respectively. i

Thepilot valve itt controls the operation of a main valve |45 (Fig. 6) and is provided with four ports |63, |41, |48 and |49, through which fluid may be directed for controlling the main valve |45. The fluid under pressure is pumped the arrow |50 by a pump I5I, driven by amotor |52. The pump |5| pumps the fluid under pressure into a main supply pipe |53, which is in communication with the port |49 of the pilot valve |44 and, when the pilot valve |44 is in the position shown in Fig. 6, where the screen is in its closed position, the passageways inthe valve Mt will direct the uid under pressure from port |49 thrugh port |43 toa port |54 in the main valve |45 to shift a slide valve member |55 to the position shown in Fig. 6. The

pilot valve |64 in the position shown in Fig. 6

will have its ports |45 arid |41 interconnected, whereby the fluid in the left end of the main valve |45 may pass through a. port |56 in the main valve, ports |41 and |40 in the pilot valve |444, to a main return pipe |51, which has a main control valve i 58 connected in it which may be operated to block the return of iiuid from the pump inFig. 6, has been in Fig. 6, iluid under pressure through upper end of the cylinder 48, as pointed ber 23 'sition, the main valve "which is normally llilot valve i 80 and a position shown, the

ysupply pipe |5|, but, when the be in the position shown in Fig. 6, where the iluid under pressure will be permittedvto pass back, to the pump I5I. y

From the foregoing, it will be apparent that when the screen is moved to its closed lD- |45 will be shifted to the position shownin Fig. 6Yto direct fluid under pressure entering `at a port |58l through a port |59 and thence through pipe 54 tothe upper end of cylinder 48, thus tending .to drive the piston 53 and plunger 14 downwardly. When the pilot valve 44 is originally operated yby the actuating arm |40 dueto the closure-'of the screen ports `|59 and |60 of a mainnvalve |6| are interconnected by a slide valve'member |62. 'I'he slide valve member |62 is normally urged to the position oppositeto that shown in Fig. 6, thereby to interconnect the ports |59 and |60, but the slide valve member |62, as shown movedto its leithand position by an operator manipulating a pilot valve |63, urged to the position opposite Fig. 6 by a return spring |64. position shown in Fig. 6, the

to that shown in However, in the ,pilotvvalve |63 has its ports- |65 and |66 interconnected and also has its ports'llil and |68 interconnected. Thus, iluid under pressure from the main supply pipe |53 will pass through. ports |66 and |65 of pilot valve |63 through port |69 of the main valve |6| and iluid in the left end ofthe main valve |6| will escape through a port |10 in the main valve |6| and ports |61 and |68 p pipe |51. With the main valve |6| in the position shown ports |58 and |59 of main valve |45 will be directed to the out here-v inbefore, and will also be directed through a port |1| in the main valve |6|, at this time interconnected with port |60, to the lower end of the cylinder 48. Thus, the uid under pressure from the main supply pipe |53 will be directed to opposite sides of the piston 53 and the difference in effective area oi' the opposite sides of the piston will result in the piston being moved more rapidly lby the differential pressure exerted thereon than would be true if the valve |6| 'and pilot valve |60, were left in their normal positions. This rapid movement is imparted to the piston 53 in order to insure that the plunger 14 will reach its proper position in the mold cham- .before theram 25 reaches the position in the pilot valve |63 to the main return shown tem will'have. time to withdraw any entrapped air from the molding chamber before the ram y25 begins to compress the ceramic material. n As soon as the plunger 14 is properly seated in the mold chamber 23, as shown in Fig. 6, thepilot valve |63 may be released to interconnect ports` |65 and |68 and ports |66 and.v |61 shifting the slide valve member |62 (Fig. 6), whereby the full pressure driven by pump will be applied end of the piston 53.

The lower ram 25 operates under control lo1 a thereof for to the right of the fluid pilot valve 80 will connect the source oi' fluid under pressure from the main ,|53 through ports |82 and |83 to the left end of the main valve |8|. Simultaneously with the supplying of iluid under pressure to the left end of the main valve |0|Lports |84 and |85 of pilot valve |80 will permit the right end of the main valve |8| to beexhausted by apparatus is in operation, will to the upper main valve |8| and, in the.

pipe |51. 'As longas .under compression between the plunger 14 and -oi'the valve |8| to the main return pipe |51.

When uid under pressure is admitted to the left end of the valve |8|, a slide valve member |86 will shift to the right (Fig. 6) to interconnect ports |81 and ports |89 and |90. The port |88 is in communication with pipe 33 and port |89 is in communication with pipe 35. Therefore. when the slide valve .member |86 is shifted to the position under pressure will be supthe fluid in the upper end of the cylinder |3 will be permitted to flow back to the pump I 5| through the ceramic material86 is the ram 25, as shown in Fig. 6, the two opposing forces will tend to compact the slug of ceramic material between the ram and plunger. As soon in Fig'. 6 in order that theexhaust sysin the position shown in raised position, the hopper 94 may be swung over as the slug is compacted, and this will occur in a denite length of time with the pressure exerted by the pistons 53 and 21 being a known amountthe position of the pilotvalve |44 may be shifted by raising the screen-| I4., thereby to raise the plunger 14. u

A complete understanding of the Iinvention may be had by reference to the following briefdescription of the mode of operation thereof. A

charge of ceramic material to be compressed may be placed in the, hopper 94 and with the screen Fig. Lythat is, in its into position directly in alignment With the cav- .ried thereby will shift the pilot valve |44 to the position shown under pressure main valve |45, causing the slide valve member |55 to shift from its right hand position to its left-hand position. as shown. When the slide valve'member |55 shifts to the position shown,

in Fig. 6, thereby to supply fluid -fiuid under pressure from the mainv supply pipe |53 will be directed to the upper end of the cylinder 48 through pipe 54. In order to increase the speed of movement of the piston 53 and ram 14, the pilotvalve |63 may be shifted to the position shown against the action of the spring |64, thus by a differential action to supply iluid under pressure to the lower end of the cylinder 48, as well as-theupper end thereof.

speed of operation of the piston 14 will be materially increased. As soon as the plunger 14 is positioned, as shown in Fig. 6, the interiorof the v mold chamber 23 will be subjected to a vacuum dueto the operation oi the stem 19, which will lift the head 18 (Fig. 4) olf/of the Seat 0| and thus any air which may be entrapped in the mold chamber 23 will be exhausted therefrom. When the plunger 14 reaches its lowest position, as shown in Fig. 6, the pilot valve |63 may b e released and the spring |64 will then return the to enter ports |66a'nd |61 and the ports 65 and |68, respectively. This will result in the shifting-of the slide valve member |62 of main valve |6| to the position opposite to that shown in Fig. 6, and a high degree of |88 and to connect v to the right end (Fig. 6) of the In this manner, the

pressure will then be exerted against the piston 53. After the plunger 14 has thus been seated in position extending in the ,molding chamber |23, pilot `valve |80 may be operated to shift main valve IBI to the position shown in Fig. 6, thus tov supply iluid under pressure through pipe 33 to the lower end of the cylinder i3, thereby to comn press the charge of ceramic material 26 between the ram 25 and the plunger l, the slide valve member |86 being shifted to the position shown in Fig. 6 when pilot valve |80 is in the position shown in Fig. 6.

After acharge of ceramic material 86 has been` 5 compressed into a slug in the molding chamber, the plunger 14 may be moved 'away from the compressed slug by raising the screen III, which will shift the pilot valve |44 to a position opposite to that shown in Fig. 6, thereby interconnecting ports |46 and |48 and ports |61 and |49 of the` that shown, thereby having caused slide valve member |62 to shift to the opposite position from that shown. While the plunger 'Il is moving upwardly, the pilot valve |80 may be left in the position shown, but the piston 21 will notmove the ram 25 upwardly at this time due to the resistanceof the slug of ceramic material 86 against upward movement. Therefore, the plunger 14 will move upwardly rapidly until it reaches its uppermost position, at which time thev pressure in the system builds up andi the piston 21 will start to move upwardly again, thereby to strip the compacted slug from the molding chamber 23. After the slug has been pushed out of the molding chamber of the ram 26 and removed, the pilot valve |80 may be rocked to the position opposite to that shown to cause the main valve I8! to shift to the position opposite to that shown, thereby to return piston 21 to its lowermost position and the apparatus will now be in condition to receive another charge of ceramic material tov be compacted therein.

enters the chamber for evacuating entrapped air What is claimed is:

1. In a molding press, a molding chamber, a plunger for sealing one end of the molding c am.. ber, a ram for compacting material agains the plunger in the `molding chamber, sealing means encircling the plunger and engageable with a surface of the vmolding chamber to deiine an evacuating chamber communicating with the molding chamber, asuction means, and a valve carried by the plunger for connecting said suction means to the evacuating chamber to evacuate entrapped air from the molding chamber.

2.-In a molding press, a molding chamber, a plunger for sealing one end of the molding chamber, a ram for compacting material against the plunger in the molding chamber, means on the plunger automatically operable when the plunger from the chamber including cooperating means on the molding chamber and plunger forming a sealed passage encircling the plunger and communicating with the molding chamber, apoppet valve'having a stem for engaging and opening the valve when the plunger enters the chamber, and a vacuum line normally closed by the poppet valve, said valve serving, upon operation, to conneet said passage with the vacuum line.

GEORGE L. CHERRY.

C. VEALE.

REFERENCES CITED l The following references are of record in the ille of this patent:

UNITED STATES PATENTS 

